Cerebral vein recovery stent

Abstract

The invention relates to a cerebral vein recovery stent, which belongs to the technical field of medical instruments, and comprises a mesh cylinder, a fixing hook and a recovery ring, the mesh cylinder is woven by mesh wires and is used for supporting cerebral veins, and one end of the mesh cylinder is an inclined opening; the fixed hook is fixed at the inclined opening of the net cylinder; the recycling ring comprises a lantern ring and a ring handle which are integrally connected, and the lantern ring is detachably hooked on the fixing hook so that the net cylinder can be conveniently recycled. The mesh cylinder is woven by the mesh wires, and one end of the mesh cylinder is an oblique opening, so that the structural reliability and the structural supporting performance can be enhanced, the biological safety and the environmental adaptability are improved, the stress stimulation to the blood vessel wall is reduced, and the adverse effect after the stent is implanted into the body of a patient for a long time is remarkably reduced; and then the fixing hook is fixed at the inclined opening of the net cylinder, and the sleeve ring of the recycling ring is detachably hooked on the fixing hook, so that the net cylinder can be conveniently recycled.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a cerebral vein retrieval stent. Background Technology

[0002] Venous sinus stenting (VSS) is suitable for patients with venous sinus stenosis. It improves cerebrospinal fluid (CSF) return and reduces intracranial pressure by dilating the narrowed sinuses. VSS is effective in treating most patients with drug-resistant or rapidly progressive intracranial hypertension (IIH) complicated by different types of venous solid stenosis; a small number of unresponsive patients may require CSF shunt surgery. Therefore, venous stenting is necessary for IIH patients with venous sinus stenosis; however, for patients whose IIH symptoms do not improve after stenting, the stent must be removed.

[0003] The support performance of a stent depends mainly on its structure and surface properties. For complex and tortuous cerebral venous systems, such as large-diameter inverted triangular luminal cross sections, highly curved transverse and sigmoid sinus structures, and superior sagittal sinus cavities containing arachnoid granules, cords, trabeculae, adhesions, and septa, the requirements for the mechanical compatibility and compliance of the stent are even higher.

[0004] Existing research reports on venous sinus stents have all used carotid and peripheral artery stents: Xact (Abbott), Wallstent (Boston Scientific), etc., all of which are off-label uses.

[0005] Therefore, it is necessary to develop safe, effective, and recyclable venous stents with independent intellectual property rights to improve the cure rate of idiopathic intracranial hypertension, reduce sequelae, and lower disability and mortality rates. This is not only of great academic significance, but also of great social and economic value.

[0006] Existing technology and its shortcomings

[0007] Application publication number: CN 113208790 A, proposes a vascular stent based on an origami mechanism, mainly used to support narrowed blood vessels, and enabling delivery and retrieval through a foldable design. The stent consists of multiple stent components connected to form a ring structure, providing support in the unfolded state (first state) and facilitating delivery or removal in the contracted state (second state). Disadvantages: The stent relies on multiple auxiliary components (such as sockets, needles, hooks, and magnetic components), which, while improving functionality, increase the complexity of assembly and operation. For example, needle insertion requires precise alignment, and it is prone to jamming or failure during intravascular operation, potentially leading to delivery failure or tissue damage.

[0008] Application publication number: CN 102488579 A, ​​proposes a hybrid structure retrievable support within a tube cavity, employing a scale-like braided structure formed mechanically or by hand. This enhances radial support and bending compliance, reduces irritation to the tube wall, and lowers axial shortening to improve positioning accuracy. However, drawbacks include: deviations in the winding angle of the annular structure or loosening of the retrievable yarn knots may lead to retrievability failure (e.g., yarn breakage or uneven head contraction). While the multi-knot design improves reliability, it increases structural complexity and may affect the compatibility of the conveying system.

[0009] Application Publication Number: CN 109700582 A. The retrieval mechanism body is a hollow cylindrical shape, made of shape memory alloy, and possesses radially retractable characteristics, facilitating its insertion into a catheter sheath for blood vessel introduction or retrieval. The body structure includes a hook head and at least two circumferentially arranged connecting cords. The hook head has two axial slits, dividing it into left and right hook heads, forming hook openings to accommodate the hooking and pulling operation of the trapping loop mechanism, ensuring effective retraction during traction. Disadvantages: The double-layer stent design (such as the alignment and overlapping of inner and outer layers and the connection of fixing points) increases manufacturing complexity, for example, requiring precise alignment welding, which may lead to reduced production yield and increased costs. The retrieval hook is located in the center of the stent, making it unsuitable for the high-viscosity, low-flow-rate cerebral venous blood flow environment, and prone to thrombosis.

[0010] Application publication number: CN 111839850 A, describes a retrievable stent with a balloon, comprising a support tube body. The body has two channels: a larger drainage channel for draining bodily fluids (such as esophageal secretions), and a smaller water delivery channel for injecting or draining saline solution into or from the balloon. The balloon covers the outer wall of the support tube and is connected to an inflation / deflation port via the water delivery channel. Shortcomings: The patent emphasizes "retrievable" and "short-term implantation," but does not specify an upper limit for the safe indwelling time of the stent, nor does it provide comparative data on the tissue effects of different indwelling durations; clinical operability needs improvement. The patent proposes superimposing a drug coating on the balloon protrusion, but does not address the mechanical stability issue of the coating at the top of the protrusion.

[0011] Application publication number: CN 114569304 A, mainly comprising a support body and a solenoid. The support body has a mesh structure formed by regularly intersecting metal wires, possessing high flexibility and supporting strength. It has proximal and distal rings at both ends, connected to the distal ring via fine filaments passing through the solenoid and proximal rings, forming a recyclable mechanism. Disadvantages: The structure is highly complex; the manufacturing process of the W-shaped or spiral blank section requires precision, potentially increasing production costs and the risk of failure.

[0012] Application publication number: CN 119074309 A. This application employs an innovative multi-layered structural design with temperature-dependent intelligent morphological transformation capabilities. The core stent body is a hollow spiral structure formed by a wavy, elastic shape memory wire (such as a nickel-titanium alloy wire). The wire's interior utilizes a segmented filling technology, alternating between sintered nickel-titanium alloy and ceramic segments within the hollow tubular structure to enhance compressive strength, wear resistance, and support performance. The austenitic termination temperature of the stent body is set at 35–37°C (close to human body temperature), and the martensite initiation temperature is 10–20°C, achieving temperature-driven dynamic behavior: at body temperature (≥35–37°C), the stent's inner diameter is at its maximum and remains stable, providing vascular support; between 10–20°C and 35–37°C, the inner diameter can be adjusted to adapt to vascular changes; at ≤10–20°C, the stent can transform into an approximately linear structure under external force, facilitating retrieval. Disadvantages: The system is highly complex to operate. Delivery and retrieval involve multiple components such as insulated catheters, balloon assemblies, and retrieval hooks. Coordination in narrowed vessels can be cumbersome, increasing procedure time and the risk of misoperation. While the temperature sensitivity of the stent facilitates retrieval, it also presents reliability challenges.

[0013] Application Publication Number: CN 109172040 A. The stent consists of a cylindrical mesh open-loop stent body and a hollow conical retrieval section. The retrieval section is composed of retrieval ribs distributed at equal angles along the central axis, integrally formed from a nickel-titanium alloy by laser engraving. This design allows the stent body to provide radial support, while the conical retrieval section provides an anchoring point for subsequent capture. The retrieval hook has a hook-shaped claw with an acute-angle fold and a contrast marker at the top, which can rotate to penetrate the gap between the retrieval ribs. Disadvantages: Multiple spatial adjustments are required (rotating the claw, pushing the outer sheath, and precise angle α alignment), which may increase the difficulty of the operation in tortuous vessels; the contrast marker is highly dependent, and if the marker falls off or shifts, capture failure may occur. The retrieval hook is located in the center of the stent, making it unsuitable for the high-viscosity, low-flow-rate cerebral venous blood flow environment, and prone to thrombosis.

[0014] Application publication number: CN 109172040 A, describes a three-layer retrievable drug-eluting stent: a tubular stent body (composed of multiple annular support rods connected by sutures) serves as the supporting framework; an inner layer of non-porous intima (PE material, 0.01–0.5 mm thick) is used to hold drugs (such as paclitaxel or rapamycin); and an outer layer of microporous adventitia (silicone or TPU material, 0.01–0.2 mm thick). The support rods are integrally formed with a retrieval hook (hook-shaped or hollow tube with a slanted opening) via connecting rods, facilitating postoperative removal. Disadvantages: The ultra-thin adventitia (minimum 0.01 mm) is prone to rupture at vascular bends, potentially leading to drug leakage or stent failure. Micropore expansion relies on uniform stent expansion, but when the lesion vessel morphology is complex, micropore expansion may be uneven, affecting the consistency of drug delivery.

[0015] Therefore, how to design a cerebral vein retrieval stent with high biosafety, good environmental adaptability and strong structural reliability is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0016] This invention provides a cerebral vein retrieval stent, which solves the technical problems of low biosafety, poor environmental adaptability and weak structural reliability of existing cerebral vein retrieval stents.

[0017] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: a cerebral vein retrieval stent, comprising: a mesh tube, a fixing hook, and a retrieval ring.

[0018] The mesh tube is woven from wire and is used to support cerebral veins, with one end being slanted. The fixing hook is fixed to the slanted opening of the mesh tube. The retrieval ring includes an integrally connected collar and a handle. The collar can be detachably hooked onto the fixing hook for convenient retrieval of the mesh tube.

[0019] The beneficial effects of this invention are: it improves the traditional cerebral vein retrieval stent structure by first using a mesh tube woven with wire (mechanical weaving or handle weaving). Since one end of the mesh tube is beveled, it can enhance structural reliability and support while improving biosafety and environmental adaptability, reducing stress stimulation to the blood vessel wall, and significantly reducing the adverse effects after long-term implantation in the patient's body. Then, it is fixed to the beveled end of the mesh tube using a fixing hook. Since the retrieval ring's collar can be detachably hooked onto the fixing hook, the mesh tube can be easily retrieved.

[0020] Based on the above technical solution, the present invention can be further improved as follows.

[0021] Furthermore, the mesh tube is woven from nickel-titanium wire.

[0022] Furthermore, the fixing hook includes a connecting rod, a hook member, and a sleeve. The connecting rod is arranged along the axial direction of the net cylinder and fixed at the oblique opening of the net cylinder. The hook member includes an integrally connected hook shank and a component part. The hook shank is welded to the connecting rod in parallel. The sleeve is welded and fixed to the hook shank and the connecting rod. The fixing hook can be detachably hooked onto the component part.

[0023] The further beneficial effect of adopting the above is that by welding the connecting rod, hook and sleeve together, the structural strength of the connection between the fixed hook and the net cylinder can be enhanced, and the net cylinder can be prevented from separating from the fixed hook when the fixed hook moves the position of the net cylinder.

[0024] Furthermore, the free end of the connecting rod, the free end of the hook shank, and the free end of the hook part are all hemispherical structures.

[0025] Furthermore, the collar and the shank are arranged at an acute angle α.

[0026] Furthermore, the acute angle α is 30–60°.

[0027] Furthermore, the collar is made of nickel-titanium alloy or platinum alloy.

[0028] Furthermore, the ring handle is provided with threads for connection with the pulling device. Attached Figure Description

[0029] Figure 1 This is a three-dimensional structural schematic diagram of a cerebral vein retrieval stent according to the present invention;

[0030] Figure 2 This is a side view of a cerebral vein retrieval stent according to the present invention;

[0031] Figure 3 for Figure 2 A magnified view of the structure at point A in the middle;

[0032] Figure 4 This is a schematic diagram of the mesh tube and connecting rod in a cerebral vein retrieval stent according to the present invention;

[0033] Figure 5 for Figure 4 A magnified structural diagram of section B;

[0034] Figure 6 This is a front view schematic diagram of the retrieval ring in a cerebral vein retrieval stent according to the present invention;

[0035] Figure 7 This is a side view schematic diagram of the retrieval ring structure in a cerebral vein retrieval stent according to the present invention.

[0036] The attached diagram lists the components represented by each number as follows:

[0037] 1. Net tube, 2. Fixed hook, 21. Connecting rod, 22. Hook piece, 221. Hook handle, 222. Component part, 23. Sleeve, 3. Retrieval ring, 31. Ring, 32. Ring handle. Detailed Implementation

[0038] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0039] like Figure 1 and 6 As shown, a cerebral vein retrieval stent includes: a mesh tube 1, a fixing hook 2, and a retrieval ring 3.

[0040] The net cylinder 1 is woven from wire mesh and is used to support the cerebral veins, with one end being slanted. The fixing hook 2 is fixed at the slanted end of the net cylinder 1. The recovery ring 3 includes an integrally connected collar 31 and a ring handle 32. The collar 31 can be detachably hooked onto the fixing hook 2 for convenient recovery of the net cylinder 1.

[0041] Specifically, the mesh cylinder 1 is woven from nickel-titanium wire.

[0042] like Figure 3 As shown, in some specific embodiments, the fixing hook 2 may include a connecting rod 21, a hook 22, and a sleeve 23. The connecting rod 21 is arranged along the axial direction of the net cylinder 1 and fixed at the oblique opening of the net cylinder 1. The hook 22 includes an integrally connected hook shank portion 221 and a component portion 222. The hook shank portion 221 is welded to the connecting rod 21 in parallel. The sleeve 23 is welded and fixed to the hook shank portion 221 and the connecting rod 21. The fixing hook 2 is detachably hooked onto the component portion 222.

[0043] like Figure 3 As shown, in some specific embodiments, the free end of the connecting rod 21, the free end of the hook shank 221, and the free end of the hook 22 can all be hemispherical structures.

[0044] like Figure 6 As shown, in some specific embodiments, the collar 31 and the handle 32 are arranged at an acute angle α.

[0045] like Figure 7 As shown, specifically, the acute angle α is 30–60°.

[0046] Specifically, the collar 31 can be made of nickel-titanium alloy or platinum alloy.

[0047] like Figure 6 and Figure 7 As shown, in some specific embodiments, the ring handle 32 is provided with threads for connection with the pulling device.

[0048] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A cerebral vein retrieval stent, characterized in that, include: A mesh tube (1) woven from wire mesh and used to support cerebral veins, one end of the mesh tube (1) being oblique; A fixing hook (2) is fixed at the slanted opening of the mesh cylinder (1); The recycling ring (3) includes an integrally connected collar (31) and a ring handle (32). The collar (31) can be detachably hooked onto the fixed hook (2) for convenient recycling of the net cylinder (1).

2. The cerebral vein retrieval stent according to claim 1, characterized in that, The mesh tube (1) is woven from nickel-titanium wire.

3. The cerebral vein retrieval stent according to claim 1, characterized in that, The fixing hook (2) includes a connecting rod (21), a hook (22), and a sleeve (23). The connecting rod (21) is arranged along the axial direction of the net cylinder (1) and fixed at the oblique opening of the net cylinder (1). The hook (22) includes an integrally connected hook shank (221) and a component (222). The hook shank (221) is welded to the connecting rod (21) in parallel. The sleeve (23) is welded and fixed to the hook shank (221) and the connecting rod (21). The fixing hook (2) is detachably hooked onto the component (222).

4. The cerebral vein retrieval stent according to claim 3, characterized in that, The free end of the connecting rod (21), the free end of the hook shank (221), and the free end of the hook (22) are all hemispherical structures.

5. A cerebral vein retrieval stent according to claim 1, characterized in that, The collar (31) and the ring handle (32) are arranged at an acute angle α.

6. A cerebral vein retrieval stent according to claim 5, characterized in that, The acute angle α is 30–60°.

7. A cerebral vein retrieval stent according to claim 1, characterized in that, The collar (31) is made of nickel-titanium alloy or platinum alloy.

8. A cerebral vein retrieval stent according to claim 1, characterized in that, The ring handle (32) is provided with threads for connection with the pulling device.

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